Implemented table check constraint for named constraints.

1. Added named constraint to create table.
2. Added check constraint to alter table statement.
3. Added CheckConstraint type.

Tests:
4. Added create table test.
5. Added alter table test.

Author: Megan Woods

src/main/java/net/sf/jsqlparser/statement/create/table/CheckConstraint.java

@@ -0,0 +1,57 @@
+/*
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2013 JSQLParser
+ * %%
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as 
+ * published by the Free Software Foundation, either version 2.1 of the 
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Lesser Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Lesser Public 
+ * License along with this program.  If not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ * #L%
+ */
+package net.sf.jsqlparser.statement.create.table;
+
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.schema.Table;
+
+/**
+ * Table Check Constraint
+ * Eg. ' CONSTRAINT less_than_ten CHECK (count < 10) '
+ * @author mw
+ */
+public class CheckConstraint extends NamedConstraint {
+    private Table table;
+    private Expression expression;
+
+
+	public Table getTable() {
+		return table;
+	}
+
+	public void setTable(Table table) {
+		this.table = table;
+	}
+
+    public Expression getExpression() {
+        return expression;
+    }
+
+    public void setExpression(Expression expression) {
+        this.expression = expression;
+    }
+
+    @Override
+    public String toString() {
+        return "CONSTRAINT " + getName() + " CHECK (" + expression + ")";
+    }
+}

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -182,6 +182,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |	<K_FOREIGN:"FOREIGN">
 |	<K_CONSTRAINT:"CONSTRAINT">
 |	<K_REFERENCES:"REFERENCES">
+|   <K_CHECK:"CHECK">
 |	<K_CHARACTER:"CHARACTER">
 |	<K_VARYING:"VARYING">
 |	<K_START:"START">
@@ -1537,6 +1538,20 @@ First First():
 	}
 }
 
+
+Expression MandatoryExpression() #Expression :
+{
+	Expression retval = null;
+}
+{
+	(
+	LOOKAHEAD(3) retval=OrExpression() | "(" retval=MandatoryExpression() ")" {retval = new Parenthesis(retval); }
+	)
+
+    { return retval; }
+}
+
+
 Expression Expression() #Expression :
 {
 	Expression retval = null;
@@ -2572,6 +2587,7 @@ CreateTable CreateTable():
 	String parameter = null;
 	Table fkTable = null;
     Select select = null;
+    CheckConstraint checkCs = null;
 }
 {
 	<K_CREATE>
@@ -2650,7 +2666,7 @@ CreateTable CreateTable():
 						}
 				)
 				|
-				(
+				LOOKAHEAD(3)(
 					{
 						fkIndex = new ForeignKeyIndex();
 					}
@@ -2671,6 +2687,17 @@ CreateTable CreateTable():
                         [LOOKAHEAD(2) (<K_ON> <K_UPDATE> (<K_CASCADE> {fkIndex.setOnUpdateReferenceOption("CASCADE");}|<K_NO> <K_ACTION> {fkIndex.setOnUpdateReferenceOption("NO ACTION");}))]
 				)
 				|
+             	LOOKAHEAD(3)(
+                    [<K_CONSTRAINT>  sk3 = RelObjectName()]
+                    {Expression exp = null;}
+                    <K_CHECK>  ("(" exp = Expression() ")")* {
+                       checkCs = new CheckConstraint();
+                       checkCs.setName(sk3);
+                       checkCs.setExpression(exp);
+                       indexes.add(checkCs);
+                       }
+                )
+				|
 				(
 					columnName=RelObjectName()
 
@@ -2951,7 +2978,7 @@ Alter AlterTable():
         (
             <K_CONSTRAINT> sk3=RelObjectName() 
 
-            ( ( tk=<K_FOREIGN> tk2=<K_KEY> 
+            ( ( tk=<K_FOREIGN> tk2=<K_KEY>
                 columnNames=ColumnsNamesList()
                 {
                     fkIndex = new ForeignKeyIndex();
@@ -2976,7 +3003,16 @@ Alter AlterTable():
                     index.setColumnsNames(columnNames);
                     alter.setIndex(index);
                 }
-            ) )
+            )
+            |
+            (
+                <K_CHECK>  {Expression exp = null;} ("(" exp = Expression() ")")* {
+                CheckConstraint checkCs = new CheckConstraint();
+                checkCs.setName(sk3);
+                checkCs.setExpression(exp);
+                alter.setIndex(checkCs);
+            }
+           ) )
         )
         )
     )

src/test/java/net/sf/jsqlparser/test/alter/AlterTest.java

@@ -65,4 +65,9 @@ public void testAlterTableDropConstraint() throws JSQLParserException {
     public void testAlterTablePK() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE `Author` ADD CONSTRAINT `AuthorPK` PRIMARY KEY (`ID`)");
     }
+
+    public void testAlterTableCheckConstraint() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE `Author` ADD CONSTRAINT name_not_empty CHECK (`NAME` <> '')");
+    }
+
 }

src/test/java/net/sf/jsqlparser/test/create/CreateTableTest.java

@@ -192,6 +192,10 @@ public void testMySqlCreateTableWithTextIndexes() throws JSQLParserException {
 		assertSqlCanBeParsedAndDeparsed("CREATE TABLE table2 (id INT (10) UNSIGNED NOT NULL AUTO_INCREMENT, name TEXT, url TEXT, created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP, updated TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (id), FULLTEXT KEY idx_table2_name (name)) ENGINE = InnoDB AUTO_INCREMENT = 7334 DEFAULT CHARSET = utf8");
 	}
 
+    public void testCreateTableWithCheck() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("CREATE TABLE table2 (id INT (10) NOT NULL, name TEXT, url TEXT, CONSTRAINT name_not_empty CHECK (name <> ''))");
+    }
+
 	public void testRUBiSCreateList() throws Exception {
 		BufferedReader in = new BufferedReader(new InputStreamReader(CreateTableTest.class.getResourceAsStream("/RUBiS-create-requests.txt")));
 		TablesNamesFinder tablesNamesFinder = new TablesNamesFinder();